Mohamud said the reported divisions were “symptomatic of a group that has lost its way”, and warned that Somalis “do not need a new brand of horror and repression”.
The Shebab, East Africa’s long-time al-Qaeda branch, is fighting to overthrow the internationally-backed government in Mogadishu, which is protected by 22 000 African Union troops.
The Islamists have lost much ground in recent years but remain a threat in both Somalia and neighbouring Kenya, where they have carried out a series of attacks.
The reported division comes at a time when Islamic State in Iraq and Syria has become the jihadist franchise of choice, attracting fighters from abroad and other militant groups such as Boko Haram in Nigeria.
But Al-Qaeda has also recently expanded its territory in Yemen, just across the Gulf of Aden from Somalia.
“Do not think that your choice is limited to one of two puppet-masters, al-Qaeda or Daesh (Islamic State),” Mohamud added. “There is another option, the right and holy option: the path to peace.”
The extent of Shabaab support for a move to ISIS is not known, while international fighters in the Shabaab have been some of the hardest hit by drone strikes and factional infighting.
Some Shebab militants are focused more on an internal Somali agenda – including navigating the Horn of Africa nation’s complex clan politics – rather than fighting for a wider international Islamist agenda.
“I will keep saying until there are no more of you left to say it to, if you feel you are within the grip of these terrorists and you want another option, stretch out your hands to the government,” Mohamud said.